Fig. to experience freedom from one's usual work schedule; to have a very enjoyable time. (As with children who are released from classes to take part in sports and athletic contests.) The boss was gone and we had afield day today. No one got anything done.The air was fresh and clear and everyone had a field day in the park during the lunch hour.
to be able to do something you enjoy a great deal, esp. criticizing someone The newspapers would have a field day if his drinking was ever widely known.
to have an opportunity to do a lot of something you want to do, especially to criticize someone The newspapers would have a field day if their affair ever became public knowledge.